Liquid, pasty or solid food products in contact with the ambient air are subject to numerous risks of biochemical or microbiological changes which are reflected by darkening, loss of taste, even of vitamins, disagreeable tastes, etc. These degradations, consequences of the presence of oxygen, are a function of the time of contact between the product and ambient air.
If these degradation phenomena are rather well controlled today, during production of the products up to the bulk storage, the risks of changes which appear during or after packaging of the finished products are still not completely eliminated; this is essentially due to difficulty of control of the parameters of handling and storing of liquid or pasty products.
To limit the risks of degradation of food products and thereby to increase the preservation period, it is essential to avoid the presence of oxygen in the product in the form of dissolved oxygen, and in its packaging in the form of gaseous oxygen. The use of an inerting technique thus seems well suited to packaging of food products.
If the present techniques of deoxygenation of food liquids by nitrogen bubbling or placing under vacuum considerably reduce the dissolved oxygen concentration, they prove insufficient at times. Actually, the action of the oxygen present in the gaseous medium is considerable and can cause degradation of products sensitive to oxidations, in particular during prolonged storage periods, particularly in the case of products intended for export.
Inerting of a packaged pasty, liquid or solid product requires elimination of the oxygen contained in the gaseous medium of the airtight packaging and of oxygen possibly dissolved before or after filling.